;;; hgnus.el --- Support Hyperbole buttons in news reader/poster: GNUS.

;; Copyright (C) 1991-1995, 2004 Free Software Foundation, Inc.
;; Developed with support from Motorola Inc.

;; Author: Bob Weiner, Brown U.
;; Maintainer: Mats Lidell <matsl@contactor.se>
;; Keywords: hypermedia, news

;; This file is part of GNU Hyperbole.

;; GNU Hyperbole is free software; you can redistribute it and/or
;; modify it under the terms of the GNU General Public License as
;; published by the Free Software Foundation; either version 3, or (at
;; your option) any later version.

;; GNU Hyperbole is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
;; General Public License for more details.

;; You should have received a copy of the GNU General Public License
;; along with GNU Emacs; see the file COPYING.  If not, write to the
;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
;; Boston, MA 02110-1301, USA.

;;; Commentary:
;;
;;   This only works with GNUS 3.15 or above, so be sure to check your
;;   newsreader version {M-ESC gnus-version RET} before reporting any
;;   problems.
;;
;;   Automatically configured for use in "hyperbole.el".
;;   If hsite loading fails prior to initializing Hyperbole Gnus support,
;;
;;       {M-x Gnus-init RTN}
;;
;;   will do it.
;;
;;
;;   Have not yet overloaded 'news-reply-yank-original'
;;   to yank and hide button data from news article buffer.

;;; Code:

;;;
;;; Other required Elisp libraries
;;;

(require 'hmail)
(require 'hsmail)
(require 'gnus-msg)

;;;
;;; Public variables
;;;

(setq hnews:composer 'news-reply-mode
      hnews:lister   'gnus-summary-mode
      hnews:reader   'gnus-article-mode)


;;;
;;; Public functions
;;;

(defun Gnus-init ()
  "Initializes Hyperbole support for Gnus Usenet news reading."
  (interactive)
  nil)

(defun lnews:to ()
  "Sets current buffer to the Usenet news article summary listing buffer."
  (and (eq major-mode hnews:reader) (set-buffer gnus-summary-buffer)))

(defun rnews:to ()
  "Sets current buffer to the Usenet news article reader buffer."
  (and (eq major-mode hnews:lister) (set-buffer gnus-article-buffer)))

(defun rnews:summ-msg-to ()
  "Displays news message associated with current summary header."
  (let ((article (gnus-summary-article-number)))
    (if (or (null gnus-current-article)
	    (/= article gnus-current-article))
	;; Selected subject is different from current article's.
	(gnus-summary-display-article article))))


;;; Overlay 'gnus-inews-article' from "gnuspost.el" to make it include
;;; any signature before Hyperbole button data.  Does this by having
;;; signature inserted within narrowed buffer and then applies a hook to
;;; have the buffer widened before sending.
(hypb:function-symbol-replace
  'gnus-inews-article 'widen 'hmail:msg-narrow)

;;; Overload this function from "rnewspost.el" for supercite compatibility
;;; only when supercite is in use.
(if (hypb:supercite-p)
    (defun news-reply-yank-original (arg)
      "Supercite version of news-reply-yank-original.
Insert the message being replied to in the reply buffer. Puts point
before the mail headers and mark after body of the text.  Calls
mail-yank-original to actually yank the message into the buffer and
cite text.  

If mail-yank-original is not overloaded by supercite, each nonblank
line is indented ARG spaces (default 3).  Just \\[universal-argument]
as ARG means don't indent and don't delete any header fields."
      (interactive "P")
      (mail-yank-original arg)
      (exchange-point-and-mark)
      (run-hooks 'news-reply-header-hook))
  )

;;;
;;; Private variables
;;;
;;;
(var:append 'gnus-Inews-article-hook '(widen))
;;;
;;; Hide any Hyperbole button data and highlight buttons if possible
;;; in news article being read.
(var:append 'gnus-article-prepare-hook
	    (if (fboundp 'hproperty:but-create)
		'(hmail:msg-narrow hproperty:but-create)
	      '(hmail:msg-narrow)))

(if (fboundp 'hproperty:but-create)
    (var:append 'gnus-summary-prepare-hook '(hproperty:but-create)))

;;; Try to setup comment addition as the first element of these hooks.
(if (fboundp 'add-hook)
    ;; Called from 'news-post-news' if prev unsent article exists and user
    ;; says erase it.  Add a comment on Hyperbole button support.
    (progn
      (add-hook 'news-setup-hook 'smail:comment-add)
      ;; Called from 'news-post-news' if no prev unsent article exists.
      ;; Add a comment on Hyperbole button support.
      (add-hook 'news-reply-mode-hook 'smail:comment-add))
  (var:append 'news-setup-hook '(smail:comment-add))
  (var:append 'news-reply-mode-hook '(smail:comment-add)))

(provide 'hgnus)

;;; hgnus.el ends here